<?php
/**
 * CDateFormatter class file.
 *
 * @author Wei Zhuo <weizhuo[at]gmail[dot]com>
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @link http://www.yiiframework.com/
 * @copyright Copyright &copy; 2008-2011 Yii Software LLC
 * @license http://www.yiiframework.com/license/
 */

/**
 * CDateFormatter provides date/time localization functionalities.
 *
 * CDateFormatter allows you to format dates and times in a locale-sensitive manner.
 * Patterns are interpreted in the locale that the CDateFormatter instance
 * is associated with. For example, month names and weekday names may vary
 * under different locales, which yields different formatting results.
 * The patterns that CDateFormatter recognizes are as defined in
 * {@link http://www.unicode.org/reports/tr35/#Date_Format_Patterns CLDR}.
 *
 * CDateFormatter supports predefined patterns as well as customized ones:
 * <ul>
 * <li>The method {@link formatDateTime()} formats date or time or both using
 *   predefined patterns which include 'full', 'long', 'medium' (default) and 'short'.</li>
 * <li>The method {@link format()} formats datetime using the specified pattern.
 *   See {@link http://www.unicode.org/reports/tr35/#Date_Format_Patterns} for
 *   details about the recognized pattern characters.</li>
 * </ul>
 *
 * @author Wei Zhuo <weizhuo[at]gmail[dot]com>
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @version $Id: CDateFormatter.php 2798 2011-01-01 19:29:03Z qiang.xue $
 * @package system.i18n
 * @since 1.0
 */
class CDateFormatter extends CComponent
{
    /**
     * @var array pattern characters mapping to the corresponding translator methods
     */
    private static $_formatters=array(
		'G'=>'formatEra',
		'y'=>'formatYear',
		'M'=>'formatMonth',
		'L'=>'formatMonth',
		'd'=>'formatDay',
		'h'=>'formatHour12',
		'H'=>'formatHour24',
		'm'=>'formatMinutes',
		's'=>'formatSeconds',
		'E'=>'formatDayInWeek',
		'c'=>'formatDayInWeek',
		'e'=>'formatDayInWeek',
		'D'=>'formatDayInYear',
		'F'=>'formatDayInMonth',
		'w'=>'formatWeekInYear',
		'W'=>'formatWeekInMonth',
		'a'=>'formatPeriod',
		'k'=>'formatHourInDay',
		'K'=>'formatHourInPeriod',
		'z'=>'formatTimeZone',
		'Z'=>'formatTimeZone',
		'v'=>'formatTimeZone',
    );

    private $_locale;

    /**
     * Constructor.
     * @param mixed $locale locale ID (string) or CLocale instance
     */
    public function __construct($locale)
    {
        if(is_string($locale))
        $this->_locale=CLocale::getInstance($locale);
        else
        $this->_locale=$locale;
    }

    /**
     * Formats a date according to a customized pattern.
     * @param string $pattern the pattern (See {@link http://www.unicode.org/reports/tr35/#Date_Format_Patterns})
     * @param mixed $time UNIX timestamp or a string in strtotime format
     * @return string formatted date time.
     */
    public function format($pattern,$time)
    {
        if(is_string($time))
        {
            if(ctype_digit($time))
            $time=(int)$time;
            else
            $time=strtotime($time);
        }
        $date=CTimestamp::getDate($time,false,false);
        $tokens=$this->parseFormat($pattern);
        foreach($tokens as &$token)
        {
            if(is_array($token)) // a callback: method name, sub-pattern
            $token=$this->{$token[0]}($token[1],$date);
        }
        return implode('',$tokens);
    }

    /**
     * Formats a date according to a predefined pattern.
     * The predefined pattern is determined based on the date pattern width and time pattern width.
     * @param mixed $timestamp UNIX timestamp or a string in strtotime format
     * @param string $dateWidth width of the date pattern. It can be 'full', 'long', 'medium' and 'short'.
     * If null, it means the date portion will NOT appear in the formatting result
     * @param string $timeWidth width of the time pattern. It can be 'full', 'long', 'medium' and 'short'.
     * If null, it means the time portion will NOT appear in the formatting result
     * @return string formatted date time.
     */
    public function formatDateTime($timestamp,$dateWidth='medium',$timeWidth='medium')
    {
        if(!empty($dateWidth))
        $date=$this->format($this->_locale->getDateFormat($dateWidth),$timestamp);

        if(!empty($timeWidth))
        $time=$this->format($this->_locale->getTimeFormat($timeWidth),$timestamp);

        if(isset($date) && isset($time))
        {
            $dateTimePattern=$this->_locale->getDateTimeFormat();
            return strtr($dateTimePattern,array('{0}'=>$time,'{1}'=>$date));
        }
        else if(isset($date))
        return $date;
        else if(isset($time))
        return $time;
    }

    /**
     * Parses the datetime format pattern.
     * @param string $pattern the pattern to be parsed
     * @return array tokenized parsing result
     */
    protected function parseFormat($pattern)
    {
        static $formats=array();  // cache
        if(isset($formats[$pattern]))
        return $formats[$pattern];
        $tokens=array();
        $n=strlen($pattern);
        $isLiteral=false;
        $literal='';
        for($i=0;$i<$n;++$i)
        {
            $c=$pattern[$i];
            if($c==="'")
            {
                if($i<$n-1 && $pattern[$i+1]==="'")
                {
                    $tokens[]="'";
                    $i++;
                }
                else if($isLiteral)
                {
                    $tokens[]=$literal;
                    $literal='';
                    $isLiteral=false;
                }
                else
                {
                    $isLiteral=true;
                    $literal='';
                }
            }
            else if($isLiteral)
            $literal.=$c;
            else
            {
                for($j=$i+1;$j<$n;++$j)
                {
                    if($pattern[$j]!==$c)
                    break;
                }
                $p=str_repeat($c,$j-$i);
                if(isset(self::$_formatters[$c]))
                $tokens[]=array(self::$_formatters[$c],$p);
                else
                $tokens[]=$p;
                $i=$j-1;
            }
        }
        if($literal!=='')
        $tokens[]=$literal;

        return $formats[$pattern]=$tokens;
    }

    /**
     * Get the year.
     * "yy" will return the last two digits of year.
     * "y...y" will pad the year with 0 in the front, e.g. "yyyyy" will generate "02008" for year 2008.
     * @param string $pattern a pattern.
     * @param array $date result of {@link CTimestamp::getdate}.
     * @return string formatted year
     */
    protected function formatYear($pattern,$date)
    {
        $year=$date['year'];
        if($pattern==='yy')
        return str_pad($year%100,2,'0',STR_PAD_LEFT);
        else
        return str_pad($year,strlen($pattern),'0',STR_PAD_LEFT);
    }

    /**
     * Get the month.
     * "M" will return integer 1 through 12;
     * "MM" will return two digits month number with necessary zero padding, e.g. 05;
     * "MMM" will return the abrreviated month name, e.g. "Jan";
     * "MMMM" will return the full month name, e.g. "January";
     * "MMMMM" will return the narrow month name, e.g. "J";
     * @param string $pattern a pattern.
     * @param array $date result of {@link CTimestamp::getdate}.
     * @return string month name
     */
    protected function formatMonth($pattern,$date)
    {
        $month=$date['mon'];
        switch($pattern)
        {
            case 'M':
                return $month;
            case 'MM':
                return str_pad($month,2,'0',STR_PAD_LEFT);
            case 'MMM':
                return $this->_locale->getMonthName($month,'abbreviated');
            case 'MMMM':
                return $this->_locale->getMonthName($month,'wide');
            case 'MMMMM':
                return $this->_locale->getMonthName($month,'narrow');
            case 'L':
                return $month;
            case 'LL':
                return str_pad($month,2,'0',STR_PAD_LEFT);
            case 'LLL':
                return $this->_locale->getMonthName($month,'abbreviated', true);
            case 'LLLL':
                return $this->_locale->getMonthName($month,'wide', true);
            case 'LLLLL':
                return $this->_locale->getMonthName($month,'narrow', true);
            default:
                throw new CException(Yii::t('yii','The pattern for month must be "M", "MM", "MMM", "MMMM", "L", "LL", "LLL" or "LLLL".'));
        }
    }

    /**
     * Get the day of the month.
     * "d" for non-padding, "dd" will always return 2 digits day numbers, e.g. 05.
     * @param string $pattern a pattern.
     * @param array $date result of {@link CTimestamp::getdate}.
     * @return string day of the month
     */
    protected function formatDay($pattern,$date)
    {
        $day=$date['mday'];
        if($pattern==='d')
        return $day;
        else if($pattern==='dd')
        return str_pad($day,2,'0',STR_PAD_LEFT);
        else
        throw new CException(Yii::t('yii','The pattern for day of the month must be "d" or "dd".'));
    }

    /**
     * Get the day in the year, e.g. [1-366]
     * @param string $pattern a pattern.
     * @param array $date result of {@link CTimestamp::getdate}.
     * @return integer hours in AM/PM format.
     */
    protected function formatDayInYear($pattern,$date)
    {
        $day=$date['yday'];
        if(($n=strlen($pattern))<=3)
        return str_pad($day,$n,'0',STR_PAD_LEFT);
        else
        throw new CException(Yii::t('yii','The pattern for day in year must be "D", "DD" or "DDD".'));
    }

    /**
     * Get day of week in the month, e.g. 2nd Wed in July.
     * @param string $pattern a pattern.
     * @param array $date result of {@link CTimestamp::getdate}.
     * @return integer day in month
     * @see http://www.unicode.org/reports/tr35/#Date_Format_Patterns
     */
    protected function formatDayInMonth($pattern,$date)
    {
        if($pattern==='F')
        return (int)(($date['mday']+6)/7);
        else
        throw new CException(Yii::t('yii','The pattern for day in month must be "F".'));
    }

    /**
     * Get the day of the week.
     * "E", "EE", "EEE" will return abbreviated week day name, e.g. "Tues";
     * "EEEE" will return full week day name;
     * "EEEEE" will return the narrow week day name, e.g. "T";
     * @param string $pattern a pattern.
     * @param array $date result of {@link CTimestamp::getdate}.
     * @return string day of the week.
     * @see http://www.unicode.org/reports/tr35/#Date_Format_Patterns
     */
    protected function formatDayInWeek($pattern,$date)
    {
        $day=$date['wday'];
        switch($pattern)
        {
            case 'E':
            case 'EE':
            case 'EEE':
            case 'eee':
                return $this->_locale->getWeekDayName($day,'abbreviated');
            case 'EEEE':
            case 'eeee':
                return $this->_locale->getWeekDayName($day,'wide');
            case 'EEEEE':
            case 'eeeee':
                return $this->_locale->getWeekDayName($day,'narrow');
            case 'e':
            case 'ee':
            case 'c':
                return $day ? $day : 7;
            case 'ccc':
                return $this->_locale->getWeekDayName($day,'abbreviated',true);
            case 'cccc':
                return $this->_locale->getWeekDayName($day,'wide',true);
            case 'ccccc':
                return $this->_locale->getWeekDayName($day,'narrow',true);
            default:
                throw new CException(Yii::t('yii','The pattern for day of the week must be "E", "EE", "EEE", "EEEE", "EEEEE", "e", "ee", "eee", "eeee", "eeeee", "c", "cccc" or "ccccc".'));
        }
    }

    /**
     * Get the AM/PM designator, 12 noon is PM, 12 midnight is AM.
     * @param string $pattern a pattern.
     * @param array $date result of {@link CTimestamp::getdate}.
     * @return string AM or PM designator
     */
    protected function formatPeriod($pattern,$date)
    {
        if($pattern==='a')
        {
            if(intval($date['hours']/12))
            return $this->_locale->getPMName();
            else
            return $this->_locale->getAMName();
        }
        else
        throw new CException(Yii::t('yii','The pattern for AM/PM marker must be "a".'));
    }

    /**
     * Get the hours in 24 hour format, i.e. [0-23].
     * "H" for non-padding, "HH" will always return 2 characters.
     * @param string $pattern a pattern.
     * @param array $date result of {@link CTimestamp::getdate}.
     * @return string hours in 24 hour format.
     */
    protected function formatHour24($pattern,$date)
    {
        $hour=$date['hours'];
        if($pattern==='H')
        return $hour;
        else if($pattern==='HH')
        return str_pad($hour,2,'0',STR_PAD_LEFT);
        else
        throw new CException(Yii::t('yii','The pattern for 24 hour format must be "H" or "HH".'));
    }

    /**
     * Get the hours in 12 hour format, i.e., [1-12]
     * "h" for non-padding, "hh" will always return 2 characters.
     * @param string $pattern a pattern.
     * @param array $date result of {@link CTimestamp::getdate}.
     * @return string hours in 12 hour format.
     */
    protected function formatHour12($pattern,$date)
    {
        $hour=$date['hours'];
        $hour=($hour==12|$hour==0)?12:($hour)%12;
        if($pattern==='h')
        return $hour;
        else if($pattern==='hh')
        return str_pad($hour,2,'0',STR_PAD_LEFT);
        else
        throw new CException(Yii::t('yii','The pattern for 12 hour format must be "h" or "hh".'));
    }

    /**
     * Get the hours [1-24].
     * 'k' for non-padding, and 'kk' with 2 characters padding.
     * @param string $pattern a pattern.
     * @param array $date result of {@link CTimestamp::getdate}.
     * @return integer hours [1-24]
     */
    protected function formatHourInDay($pattern,$date)
    {
        $hour=$date['hours']==0?24:$date['hours'];
        if($pattern==='k')
        return $hour;
        else if($pattern==='kk')
        return str_pad($hour,2,'0',STR_PAD_LEFT);
        else
        throw new CException(Yii::t('yii','The pattern for hour in day must be "k" or "kk".'));
    }

    /**
     * Get the hours in AM/PM format, e.g [0-11]
     * "K" for non-padding, "KK" will always return 2 characters.
     * @param string $pattern a pattern.
     * @param array $date result of {@link CTimestamp::getdate}.
     * @return integer hours in AM/PM format.
     */
    protected function formatHourInPeriod($pattern,$date)
    {
        $hour=$date['hours']%12;
        if($pattern==='K')
        return $hour;
        else if($pattern==='KK')
        return str_pad($hour,2,'0',STR_PAD_LEFT);
        else
        throw new CException(Yii::t('yii','The pattern for hour in AM/PM must be "K" or "KK".'));
    }

    /**
     * Get the minutes.
     * "m" for non-padding, "mm" will always return 2 characters.
     * @param string $pattern a pattern.
     * @param array $date result of {@link CTimestamp::getdate}.
     * @return string minutes.
     */
    protected function formatMinutes($pattern,$date)
    {
        $minutes=$date['minutes'];
        if($pattern==='m')
        return $minutes;
        else if($pattern==='mm')
        return str_pad($minutes,2,'0',STR_PAD_LEFT);
        else
        throw new CException(Yii::t('yii','The pattern for minutes must be "m" or "mm".'));
    }

    /**
     * Get the seconds.
     * "s" for non-padding, "ss" will always return 2 characters.
     * @param string $pattern a pattern.
     * @param array $date result of {@link CTimestamp::getdate}.
     * @return string seconds
     */
    protected function formatSeconds($pattern,$date)
    {
        $seconds=$date['seconds'];
        if($pattern==='s')
        return $seconds;
        else if($pattern==='ss')
        return str_pad($seconds,2,'0',STR_PAD_LEFT);
        else
        throw new CException(Yii::t('yii','The pattern for seconds must be "s" or "ss".'));
    }

    /**
     * Get the week in the year.
     * @param string $pattern a pattern.
     * @param array $date result of {@link CTimestamp::getdate}.
     * @return integer week in year
     */
    protected function formatWeekInYear($pattern,$date)
    {
        if($pattern==='w')
        return @date('W',@mktime(0,0,0,$date['mon'],$date['mday'],$date['year']));
        else
        throw new CException(Yii::t('yii','The pattern for week in year must be "w".'));
    }

    /**
     * Get week in the month.
     * @param array $pattern result of {@link CTimestamp::getdate}.
     * @param string $date a pattern.
     * @return integer week in month
     */
    protected function formatWeekInMonth($pattern,$date)
    {
        if($pattern==='W')
        return @date('W',@mktime(0,0,0,$date['mon'], $date['mday'],$date['year']))-date('W', mktime(0,0,0,$date['mon'],1,$date['year']))+1;
        else
        throw new CException(Yii::t('yii','The pattern for week in month must be "W".'));
    }

    /**
     * Get the timezone of the server machine.
     * @param string $pattern a pattern.
     * @param array $date result of {@link CTimestamp::getdate}.
     * @return string time zone
     * @todo How to get the timezone for a different region?
     */
    protected function formatTimeZone($pattern,$date)
    {
        if($pattern[0]==='z' || $pattern[0]==='v')
        return @date('T', @mktime($date['hours'], $date['minutes'], $date['seconds'], $date['mon'], $date['mday'], $date['year']));
        elseif($pattern[0]==='Z')
        return @date('O', @mktime($date['hours'], $date['minutes'], $date['seconds'], $date['mon'], $date['mday'], $date['year']));
        else
        throw new CException(Yii::t('yii','The pattern for time zone must be "z" or "v".'));
    }

    /**
     * Get the era. i.e. in gregorian, year > 0 is AD, else BC.
     * @param string $pattern a pattern.
     * @param array $date result of {@link CTimestamp::getdate}.
     * @return string era
     * @todo How to support multiple Eras?, e.g. Japanese.
     */
    protected function formatEra($pattern,$date)
    {
        $era=$date['year']>0 ? 1 : 0;
        switch($pattern)
        {
            case 'G':
            case 'GG':
            case 'GGG':
                return $this->_locale->getEraName($era,'abbreviated');
            case 'GGGG':
                return $this->_locale->getEraName($era,'wide');
            case 'GGGGG':
                return $this->_locale->getEraName($era,'narrow');
            default:
                throw new CException(Yii::t('yii','The pattern for era must be "G", "GG", "GGG", "GGGG" or "GGGGG".'));
        }
    }
}
